With the rapid development of semi-illumination technologies, people's demands on illumination devices are higher and higher. Currently, according to an illuminating angle, a ceiling lamp may be a downlight or a spotlight. As an illuminator which is embedded in a ceiling and emits downward light rays, the downlight has the advantage of keeping uniform and perfection architectural ornament, and the artwork in the ceiling may not be affected by the arrangement of lamps. On the other hand, light rays from the spotlight directly illuminate on household objects to be highlighted, so as to emphasize subjective aesthetic sense and achieve art effects of highlighted key points, unique environments, rich layers and atmosphere, and plentiful colors. The spotlight may have soft light rays, and is both dignified and graceful, which not only dominates the whole illumination, but also enables the local lighting and heightens the atmosphere inside the house.